<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>all</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const all = (arr, fn = Boolean) => arr.every(fn);
        console.log(all([4, 2, 3], x => x > 1)); // true
        console.log(all([1, 2, 3])); // true
        console.log(all([1, 2, 3], x => x < 2)); //false
    </script>
</body>

</html>